Prince George's County's state legislators heard several hours of testimony last night on a bill that would allow the financially strapped county government to increase a special tax rate that would bring in an estimated $10.8 million, most of it from utility companies.

Most of the 30 speakers at the public hearing favored the measure. The principal opposition came from utility companies--representatives of the Potomac Electric Power Co., the Washington Gas Light Co. and the Chesapeake and Potomac Telephone Co.--plus the county Chamber of Commerce.

The measure, drafted by County Executive Parris Glendening in an effort to defray a projected $35 million deficit, would allow the county to increase the tax rate on what the tax law defines as personal property--such things as trucks, equipment for generating power and business machines like cash registers and computers.

Speakers representing education, labor, and mental health and similar groups generally defended the bill as an equitable solution to the county's problems.

County health officer Dr. Helen McAllister said the Health Department could face layoffs of up to 75 people if the county does not get more revenue. "There is no one who can speak for those who are not ill but would be ill if you didn't have us," she said.

County Board of Education Chairman Susan Bienasz and at least a half a dozen other speakers said the county faces a crisis in education, particularly in light of layoffs of county teachers last year.

James J. Doyle, lobbyist for Pepco, called the bill illogical and inequitable. He said that Pepco is the largest property taxpayer in Prince George's, having paid $16 million last year, and that increased costs would be passed along to consumers. He said "148,000 customers would be called upon to subsidize services for the rest of the county and this is not the way to do it."

Last night's hearing was on one of two revenue measures introduced by Glendening to raise money for the county. The other would allow the county to raise its surcharge on the state income tax from 50 percent to 60 percent. A hearing on that measure is scheduled for Feb. 16.